TIP: "special" indoors camera, faster render times

alaltacc

Hello!

   A tip that, for me as a newbie, is helping a lot! I'm always trying to avoid rendering indoors scenes, as the props, walls and lighting make the rendering time go through the roof. When I do, I try to hide everything that's not in the field of view to make things faster (lots of work)

   Yesterday I found this camera by chance:

https://www.deviantart.com/heroineadventures/art/Iray-Interior-Camera-V1-3-758604718

   Basically, it's a camera with planes attached around it. These planes "cut" through the scene (outside the field of view), therefore blocking light to and from this field of view and making rendering times sometimes 8x to 10x faster with basically the same results.

   A few caveats, some of them from the author himself:

- You need to avoid looking directly to high-reflection surfaces like mirrors (side views are OK), otherwise the "cutting" of the planes will show

- If you have very complex lighting BEHIND the camera the final result will be different (not necessarily worse) in terms of look. Sometimes, close-ups don't work so well.

- If you use more than one of these cameras in the scene, you need to completely hide (CTRL + hide) all the cameras but the one you're using, since they "cut" the objects in the scene and this will show in your other cameras

   For me, this was a game changer. Hope this helps someone else!

 

Gordig

You can create the same effect yourself; it's called an Iray Section Plane, and they're in the Create menu.

alaltacc

Yes, but I would need to create and align four of them to do the same. This is ready to use.

Togire

This product is excellent (and it is free). Also great for outdoor scene to remove useless items not seen in the scene. Generally, I use one or several normal cameras for the framing and when I am happy with the result, I copy the cam parameters to the iray interior camera and I render. This way I can have only one cam with parented iray section planes.

Only problem, the focal length of this cam is fixed and cannot be changed without moving the iray section planes (and it is a PITA). Riversoft has recently issued a similar item ("camera cutaway") that does not have this problem.

function

I thought one problem for 'iray section plane' is, your indoor scene can not contains windows, which means you can not use HDRI environment, otherwise when you 'cut' the building, those environment light will coming in and generate weird shadows or make the room too bright.

alaltacc

It depends a lot from where the light is coming, as the planes block a good chunk of the light that comes from behind it. But yes, it can change the lighting not only from the HDRI but also from inside, as it blocks (again) the light from behind the camera. even the scene lights. In close-ups this is more noticeable, but it's always a good idea to do a preview with a normal camera and this one and compare before rendering, especially if you are using subtle or complex lighting and trying to achieve a specific result.